Various embodiments of life-raft laid out in this way are already known (see, for example, documents U.S. Pat. No. 4,998,900, FR 2,467,770, GB 2,060,509).
However, in these known structures, the hoops, of which there are two, extend in secant vertical planes and form a cupola shape over the raft. A layout of this kind is suitable only for rafts which have a fairly compact shape (with an outline that is square, polygonal--especially hexagonal or octagonal--, rectangular with not much elongation, circular) and are of a relatively small size. It is not suitable for rafts of elongate shape, especially for rafts of very large size (high- or extremely high-capacity rafts taking, for example, 50, 100 or 150 people) which are currently needed for fitting out vessels (such as cruise liners, car ferries) from which passengers need to be able to be evacuated extremely fast: on the one hand, the cupola layout of the secant hoops cannot be applied to large-sized rafts and, what is more, if a layout of this kind were to be associated with an elongate shape (rectangular overall) of the raft, two "dead" positions would be defined, from which the raft, laying on its side or especially on an end, would not be able to tip right over.